In typical halogenation reactions of olefin or halo-olefin compounds (i.e., organic), an excess amount of halogen gas (fluorine, chlorine, bromine, iodine, or their combinations) is normally used in order to achieve maximum halogenation of the organic. In a conventional halogenation process, one reactor is used and the excess halogen gas in the off-gas stream is scrubbed by a caustic solution. This increases the consumption of halogen and generates waste for later disposal. The present invention is directed to a novel process which permits recovery of the excess halogen gas, which thereby reduces the operating cost of the reaction.